This section is from the "Elixirs And Flavoring Extracts. Their History, Formulae, & Methods of Preparation" book, by John Uri Lloyd. Also available from Amazon: Elixirs and flavoring extracts,: Their history, formulae, and methods of preparation;
Cinchonine (alkaloid), 256 grains.
Simple elixir, phosphoric acid (U. S. P., 1872), of each a sufficient quantity.
Triturate the powdered cinchonine in a mortar with three fluidounces of simple elixir, and dissolve it by the gradual addition of a sufficient amount of phosphoric acid; then mix this solution with a sufficient amount of simple elixir to make the whole measure sixteen fluidounces, and filter if necessary.
Each fluidrachm (teaspoonful) of the finished elixir contains of phosphate of cinchonine an amount which is equivalent to two grains of cinchonine.